A former Saudi intelligence chief Prince Bandar bin Sultan was linked to an al-Qaeda operative, US probe into the 9/11 terrorist attack revealed.

“The presence of a contact number linked to a company associated with Prince Bandar bin Sultan in the phone log of an al-Qaeda suspect is one of the most stunning parts of the investigation,” the co-chair of the report said.

An alleged top al-Qaeda operative, Abu Zubaydah, maintained a phone log which included phone number of a Colorado company associated with Bandar as well as the phone number of a bodyguard working at the Saudi Embassy in the United States at the time, CNN reported.

After Bush administration refused to publish the 28 pages that were the result of an investigation into the 9/11 attacks, the Obama administration released the documents in July this year.

The company, which is located in Aspen, Colorado, used to manage Prince Bandar’s estate in the Western US state.

“Both of those numbers were unpublished, so they had to have gotten into Zubaydah's phone book through a personal contact who knew what those numbers were and what they represented,” said the co-chair of the report, former Senator Bob Graham.

The CIA and FBI, however, concluded there was no evidence showing that anyone from the Saudi royal family knowingly provided support for the 9/11 attacks.

Saudi Arabia has denied allegations made against them as being involved in the 2001 terrorist attacks that killed nearly 3,000 people in New York, Washington, and Pennsylvania.